Echocardiographic findings of tricuspid blood cyst mimicking bacterial endocarditis in a dairy cow

The most common endocardial disease in cattle is bacterial endocarditis. The diagnosis of the disease in living animals is mainly based on clinical findings and echocardiographic detection of an irregularly thickened valve. Despite its presumed good sensitivity, little is known on the specificity of transthoracic echocardiography with regards to endocarditis. This case report describes the echocardiographic findings in a dairy cow diagnosed with a chronic inflammatory process, liver and splenic abscesses and tricuspid valve blood cysts that can be mistaken for bacterial endocarditis, thus emphasizing the need to improve antemortem diagnostic tools for endocarditis in cattle.     

Spatial variability of the functional stability of microbial respiration process: a microcosm study using tropical forest soil

Purpose

Understanding the ability of ecosystem processes to resist to and to recover from disturbances is critical to sustainable land use. However, the spatial variability of the stability has rarely been addressed. Here, we investigated the functional stability of a soil microbial process for 24 soils collected from adjacent locations from a 0.3?ha tropical rainforest plot in Paracou, French Guiana.

Materials and methods

The 24 locations were characterized regarding soil chemical and biological (microbial diversity) parameters and forest structure. The corresponding soils were submitted to an experimental transient heat disturbance during a microcosm experiment. The response of the respiration process was followed using substrate-induced respiration (SIR).

Results and discussion

The response of soil SIR to heat disturbance varied widely between samples. The variability of the SIR response increased just after the disturbance, and a global rather homogeneous decrease in SIR rates was observed 15 and 30?days after. The stability of SIR in response to heat disturbance could not be related to either the genetic or the metabolic diversity of the microbial community. The initial level of SIR before the disturbance was the soil variable that best correlated with the impact of the disturbance: the soil locations with the highest initial SIR rates were the most affected 15 and 30?days after the heat disturbance.

Conclusions

Such a heterogeneous response suggests that the response of soil processes to a disturbance will be difficult to assess from only local-scale analyses and highlights the need for spatial explicitness in understanding biogeochemical processes.     

High temperature effects on hypersensitive resistance to Tomato Spotted Wilt Tospovirus (TSWV) in pepper (Capsicum chinense Jacq.)

The tomato spotted wilt virus resistance in pepper conferred by the Tsw gene is less stable at 32 °C continuous temperature. Continuous high temperatures for at least nine days lead to systemic spread and necrotic symptoms in plants that are totally resistant at a lower temperature (22 °C). We show that continuous high temperatures destabilize this resistance in young plants, but older inoculated plants rarely develop systemic symptoms. Populations segregating for the Tsw gene showed that heterozygosity at the Tsw locus increased the chance of inoculated seedlings to develop systemic necrotic symptoms. Genetic background was less significantly involved in the thermosensitivity of the resistant response. As a consequence, it would be preferable to grow cultivars homozygous at the Tsw locus in high temperature conditions.     

Impact of oral melatonin on the electroretinogram cone response

Background  

In the eye, melatonin plays a role in promoting light sensitivity at night and modulating many aspects of circadian retinal physiology. It is also an inhibitor of retinal dopamine, which is a promoter of day vision through the cone system. Consequently, it is possible that oral melatonin (an inhibitor of retinal dopamine) taken to alleviate circadian disorders may affect cone functioning. Our aim was to assess the impact of melatonin on the cone response of the human retina using electroretinography (ERG).     

Evaluation of the pollution by organochlorinated compounds (polychlorobiphenyls and pesticides) and metals (Cd,Cr, Cu and Pb) in the water and in the zebra mussel (Dreissena polymorpha pallas) of the river Seine.

The relationships between some organochlorines and metals in the water and in the zebra mussel of the river Seine have been studied in the Parisian area. The bioconcentration of PCBs by the mussel (Kb = 17 × 10³) was about 10 fold higher than for other organochlorines. The accumulation and the release response of the mussel to alterations of the water organochlorine levels occurred within a period smaller than 7 days. The correlation between the water and the mussel levels is highly significant for γHCH and PCBs (r=0.94, p<0.01 and r=0.87, p<0.05, respectively). The Pb bioconcentration (0.15 × 103) was about 20 fold lower than the Cu and Cr (3.4 and 3.0 × 10³, respectively). The Cu and the Pb levels in the water and in the mussel followed a parallel course. Cu and Pb appear to be taken up and released relatively rapidly within a 7 day period. Comparisons between the different stations along the river Seine showed that the highest pollutant evels in the water were found downstream Paris and were fairly well reflected by the mussel levels. However, when pollution reaches top values, the mussel metabolic activities are affected and thus, the bioconcentration ability too.     

Comparison of 2-step laparoscopy-guided abomasopexy versus omentopexy via right flank laparotomy for the treatment of dairy cows with left displacement of the abomasum in on-farm settings

OBJECTIVE: To compare characteristics and results of 2-step laparoscopy-guided abomasopexy versus omentopexy via laparotomy in the right paralumbar fossa for the treatment of dairy cows with a left displaced abomasum (LDA). DESIGN: Prospective clinical trial. 253 dairy cows with an LDA. PROCEDURES: All cows that were treated with omentopexy (n = 101) or 2-step laparoscopy-guided abomasopexy (152) from July 2005 through December 2006 were included. Presurgical, perisurgical, and postsurgical information was recorded by attending veterinarians. Producers were interviewed by telephone 7 and 60 days after surgery regarding the response of cows to surgery. Characteristics of and responses to the 2 surgical techniques were compared. RESULTS: At 7 days after surgery, the 2 groups of cows were not significantly different with respect to appetite, comfort, and milk yield; at 60 days after surgery, groups were similar with respect to milk yield, cull rates, and risk of relapse of LDA. Antimicrobial treatment in response to postsurgical pyrexia was necessary in only 20.4% (31/152) of cows that were treated with 2-step laparoscopy-guided abomasopexy. Mean duration (preparation and surgery) of 2-step laparoscopy-guided abomasopexy was significantly less than that of omentopexy (36 vs 74 minutes, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: Results of 2-step laparoscopy-guided abomasopexy and omentopexy via laparotomy in the right paralumbar fossa were not significantly different. Compared with omentopexy, laparoscopy-guided abomasopexy was performed more quickly and required postsurgical administration of antimicrobials less frequently. Although these factors may be of economic consequence to veterinarians and producers, other aspects must also be considered when choosing between techniques.     

Relationship between biological parameters and bioaccumulation of some organochlorines (pesticides,PCB) by fishes in the River Seine (France)

The accumulation of organochlorine compounds (α, β and γ HCH, HCB, pp'DDE pp'DDT and polychlorobiphenyls) by fishes of two different species, the Roach (Rutilus rutilus) and the Perch (Perca fluviatilis), predator of the Roach, have been studied at two stations situated on the catchment basin of the Seine. Only polychlorobiphenyls show high contents in these fishes. The polychlorobiphenyl compositions of these organisms correspond to those found in most environments. There is no systematic relationship between the bioconcentration and the size of the fish. The reproductive cycle appears to have a significant impact on the organochlorine contents. Moreover, the extent of PCB amplification with trophic level depends partly on the mode of expression of their contents, related either to body weight or to lipid weight. Thus the PCB body contents in the Perch are slightly higher than in the Roach, whereas, regarding lipid weight, the contents are twice as high as in the predator species. In the Roach, body contents of micropollutants are only two six times higher than in Molluscs (Anodonta cygnea, Vivipara vivipara). The Roach and the zebra mussel show important differences in the PCB composition, whereas there are none between the Perch and the Roach; in the latter species, they do not seem to change with age.